Bug Description

I am trying out unity on Lucid. Logging into the unity session I can see the window manager flashing like it keeps restarting. In a failsafe xterm I can start mutter fine. But when I try to run "unity" it quits after some time:

... is perfectly legal and works e.g. with intel's free driver and on nvidia's binary one.

Since I've no working ATI-graphics-card here right now, I can't debug the two driver to see what's exactly causing this call to fail. But my guess is that the two drivers cannot handle non-power-of-two textures correctly in this case. Working around this inside clutk isn't recommended, as "polluting" application/library code with work-arounds to cover up short-comings in OpenSource-drivers isn't reasonable.

A work-around could make use of the explicit texture-target GL_TEXTURE_RECTANGLE_ARB (form the GL_ARB_texture_rectangle extension). But that would require using non-normalized texture-coordinates everywhere in clutk too.

I confirm this behaviour for a Radeon 9800 Pro (R350) that runs on the radeon driver and marking the source package xserver-xorg-video-ati as a candidate to this bug. Feel free to mark the package xserver-xorg-video-radeonhd too if you encounter same kind of problem for that driver.

On 13/08/10 08:02, Tormod Volden wrote:
> Mirco, does that mean that Canonical does not care if unity is broken on
> ATI cards?

Obviously not, and it's somewhat inflammatory to put it that way, please
don't do that.

The focus for Unity in 10.10 is to get it working in the
easiest-to-support cases, especially hardware that is common in
netbooks. The Intel chips are the strongest focus, because they
generally have open source drivers and are widely used in netbooks.

It was a real question from my side, since the bug was simply closed instead of reassigned or retargeted (before somebody else opened an -ati task). Thanks for clarifying your intentions.

Anyway, I tested with latest mesa git (and all lucid and unity updates) now, and it does not crash any longer! So I will mark this as fix committed in the expectation that we get mesa 7.9 in maverick and and check again once we are there.

The extension "GL_ARB_texture_non_power_of_two" seems to be disabled by default and when enabling that one (MESA_EXTENSION_OVERRIDE=GL_ARB_texture_non_power_of_two unity) UNE is started and the left-side panel (dock) gets visible but with unreadable/corrupted launchers and comments.

Any window on the desktop leaves a white area when moved/closed. Those white areas can be fixed by adding "CLUTTER_VBLANK=none" too to the user's .profile.

Futhermore , there are other issues such as corruption och top-panel icons when eg pressing the ubuntu-logo, corrupted window shadows, poor refresh of the desktop panel/dock etc which I assume are side-effects too of the same problem.

When I reported the bug I was getting the crash both with classic and gallium. But Robert is right, it only got fixed with gallium. Classic crashes like before, and it seems now we are stuck with classic for 10.10.

Mesa 7.9 that is required seems to have been postponed to Natty Narwhal (11.04).

For those who want to try out the Maverick Netbook Edition (UNE) and are stuck with an ATI board that does cause a white screen there may be a workaround by installing the xorg-edgers for Maverick, of course on your own risk.

We're closing this bug since it is has been some time with no response from the original reporter. However, if the issue still exists please feel free to reopen with the requested information. Also, if you could, please test against the latest development version of Ubuntu, since this confirms the bug is one we may be able to pass upstream for help.